MXPA99010350A - Identification of touch point for clutch maestro de vehic - Google Patents

Abstract

A control for a traction line (10), including an automatic clutch (14), uses an electronic data link (DL) to identify the value of a clutch control parameter (PWM) that corresponds to the clutch touch point

Description

IDENTIFICATION OF TOUCH POINT FOR CLUTCH VEHICLE MASTER BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to controls for vehicle master clutches, preferably wet friction clutches, used in partially or fully automated mechanical transmission systems. In particular, the present invention relates to a touch point identification method / system using an electronic data link. DESCRIPTION OF THE STATE OF THE ART [0002] Partially automated and fully automated vehicle transmission systems are known in the state of the art, using friction master clutches, as can be seen by reference to U.S. Patent Nos. 4,361,060; 4,595,986; 4,850,236; 4,648,290; 5,389,053; 5,487,004; 5,487,005; and 5,509,867, the disclosures of which are incorporated herein by reference. Controls are known for automated friction master clutches, usually dry friction clutches, used in automated vehicle transmission systems, as can be seen by reference to U.S. Patent Nos. 4,081,065; 4,646,891; 4,860,861; 5,275,267; ,293,316; 5,314,050; 5,337,868; 5,337,874; 5,383,823; 5,393,274; 5,411,124; 5,404,301; 5,630,773; 5,624,350; and 5,738,609, the disclosures of which are incorporated herein by reference. SUMMARY OF THE INVENTION According to the present invention, a control is provided for an automated friction master clutch, such as a wet friction clutch, which utilizes the information available in vehicle data links, industry standard, such as data links that comply with the protocols, SAE J1922, SAE J1939 and / or ISO 11898, to provide improved clutch control and improved clutch functional characteristics compared to the state of the art. In particular, a clutch touch point, also called the incipient bonding point, is determined by detecting and / or controlling engine speed and steering torque using an electronically controlled engine connected to an industry standard data link ( see U.S. Patent No. 5,509,867, the disclosure of which is incorporated herein by reference). Accordingly, it is an object of the present invention to provide an improved clutch control method / system which uses the control and information available in an electronic data link to determine the value of a clutch control parameter corresponding to the touch point of clutch.

This and other objects and advantages of the present invention will be apparent from a reading of the following description of the preferred embodiment, taken in conjunction with the accompanying drawings. Brief Description of the Drawings Figure 1 is a schematic illustration of an automated vehicle mechanical transmission system, which advantageously utilizes the touch point identification control of the present invention. Figure 2 is a schematic illustration of a pressure fluid operated control mechanism for controlling the linked condition of a vehicle master clutch. Figure 3 is a partial sectional view of a wet friction master clutch for vehicle, of the type used in the system of Figure 1. Figure 4A is a schematic illustration of the touch point identification control system, which includes both hardware and software (shown in dotted blocks). Figure 4B is a graph illustrating a linear relationship between the torque transfer capacity and values of the clutch control parameter (PWM). Figure 5 is a schematic illustration, in flow chart format, of the touch point identification control logic of the present invention.

Description of the Preferred Embodiment Form An automated mechanical transmission system 10, for vehicle, which advantageously uses the touch point identification control of the present invention, is schematically illustrated in Figure 1. System 10 includes a fuel controlled engine 12, a wet friction master clutch 14 and a mechanical transmission multi-speed motor 16. Motor 12 is typically a diesel or petrol engine and has an output member or crankshaft 18 that drives friction discs 14A of clutch 14, which are inter-digitized with friction discs 14B, rotationally fixed to the input arrow 20 of the transmission 16. The transmission 16 may be of the simple or composite type, as illustrated in U.S. Patent No. 5,370,561, the disclosure of which is incorporated herein by reference. The transmission 16 has an exit arrow 22, which drives a pulling arrow 24 connected to the inlet 26 of a drive shaft mechanism 27 of the vehicle. An engine controller 28, which is preferably electronically controlled and "by a microprocessor, is provided to control the fuel supply of the engine and to provide output information to an electronic data link DL, preferably complying with the standard of SAE J1939 industry or a comparable protocol The system 10 also includes a clutch actuator 30 for controlling the operation of the clutch 14 and a transmission actuator 32 for controlling the operation of the transmission 16. A sensor 33 is provided for detecting the position of throttling and providing a THL signal indicative thereof The information about the throttle position can also be obtained from the data link The electronic motors controlled by a SAE data link J1939 or similar typically have four operating modes, ( i) fuel according to the choke position, (ii) fuel according to on the requested engine speed, (iii) fuel according to the gross torque requested from the engine, and (iv) fuel according to the engine speed requested and the gross torque requested from the engine. A microprocessor-based control unit 34 is provided to receive input signals 36 and process them according to control logic to generate command output signals 38 to system actuators. The ECU 34 can be separated from or integral with the motor controller. The various controllers, sensors and / or actuators can communicate via a data link that complies with an industry standard protocol, such as SAE J1939 or the like. Suitable sensors, such as sensors for detecting the speed of the motor ES, the speed of the input arrow IS and / or the speed of the output arrow OS, and actuators, are known to those skilled in the art and examples thereof. , not intended to be limiting, may be seen by reference to United States Patents Nos. 4,361,060; 4,873,881; 4,974,468; 5,135,218; 5,279,172; 5,305,240; 5,323,669; 5,408,898; 5,441,137; 5,445,126; 5,448,483, and 5,481,170. The clutch 14 is defined as a "wet clutch" ', since its friction members 14A and 14B are exposed to liquid, such as synthetic Dextron III oil or the like, for heat transfer and / or lubrication purposes. In the illustrated embodiment, the clutch pack 14C is contained within a housing 14D, which is connected to the source conduit 14E and a discharge conduit 14F. Although a forced cooling system is illustrated, the present invention is also applicable to wet clutches where the friction members are in a relatively static sump or the like. Although the preferred embodiment uses a multi-disc wet clutch 14, the present invention is also applicable to single-disc wet clutches and / or dry clutches. As is known (see the aforementioned U.S. Patent No. 5,509,867), a data link that complies with the SAE J1939 protocol, or a comparable protocol, transmits information by which the output torque of the motor can be read or determined. (also called "steering wheel twist"). These data links also allow a command to the engine to adjust the fuel feed such that a particular engine speed and / or a particular engine torque is achieved. Using this information and the motor control capability, the master clutch 14 can be controlled to provide increased system performance. A clutch actuator assembly, operated by fluid pressure 30, is illustrated schematically in Figure 2. A clutch operator piston 42 is received in a cylinder 44 and is biased in the direction of spring disengagement 46. Pressure fluid, such As a hydraulic fluid or pressurized air, introduced into the chamber 48, it will act on the piston face 50 to move the piston 42 in the linked direction against the polarization of the springs. A three-way, two-position, solenoid-controlled valve 52 is provided to selectively pressurize and discharge the chamber 48. A valve controller 54 responds to control signals from the system controller 34, energizing the solenoid 52A of the valve 52, preferably by pulse width modulation (PWM). Although a pressure fluid type actuator assembly 30 is illustrated, the present invention is also applicable to clutch controls using other types of clutch actuators, such as ball ramp actuators or the like (see U.S. Patent Nos. 5,441,137 and 5,485,903, the disclosures of which are incorporated herein by reference).

The friction material of the clutch discs 14A and 14B may be a standard material or may be pyrolytic carbon, as described in U.S. Patent No. 4,700,823, or the like. The structure of a typical wet friction master clutch 14 can be seen by reference to Figure 3. Briefly, the output of the engine 18, shown as a cushioned flywheel, is connected to the input shaft 20 of the transmission by the disk pack of friction connectable and detachable 14C. The clutch is contained within a housing 14D, which will maintain the lubricating and cooling fluid, such as synthetic Dextron III oil or the like. The annular piston 42 is slidably and sealingly contained in a cylinder 44 and biased in the direction disengaged by the springs 46. The system 10 may also include an inertia brake, also known as an inlet arrow brake or a speed change brake. upper 60, to decelerate or stop the input arrow 20 for faster higher speed changes. Inertia brakes are known, as can be seen by reference to U.S. Patent Nos. 5,086,659 and 5,713,445. Clutch controls, including techniques for identifying the clutch touch point (also known as an incipient attachment point) are known in the state of the art, as can be seen by reference to the aforementioned US Patents Nos. 4,646,891; 5,337,868; 5,337,874; 5,393,274; and 5,411,124. In accordance with the present invention, a method is provided for identifying a control parameter (such as the value of a signal pulse modulated in width to a control valve) corresponding to the clutch touch point, using an electronic data link. . Figure 4A outlines the entire touch point identification control system, which comprises both hardware and software (shaded blocks). The function of the motor control loop is to maintain (or control) the motor speed (ES) to a desired value. Inertia brake 60 is the device designed to encourage or stop the rotation of the input shaft 20 of the transmission. To link the clutch 14, the pressure controller will send a PWM command to the solenoid-operated hydraulic system, which in turn pressurizes the clutch piston 42 to engage the clutch. Within a certain range of values, the torque capacity of the linked clutch is proportional or substantially proportional to the PWM command. As is well known, the output of the motor or torsion of the flywheel (^) is equal to the gross torque of the engine (TEG) minus the sum of motor torsion losses (TL), such as the friction torque of the engine, the torsion of accessories, etc. The value of the sum of motor torsion losses, at idle speed, can be determined by determining the value of the gross torque of the engine when the clutch is fully disengaged (consequently, the steering torque is equal to zero) and the motor speed is stabilized at idle speed (TEG = TL if TM = 0). With a known value of torsion losses (TL) at idle speed, the value of the output torque, at a stabilized vacuum speed, will be equal to the value of the gross engine torque minus the known value of torsion losses (T ^ = TEG - TL). Accordingly, a specific engine output torque (Tp ,,), at a given engine speed, can be ordered by ordering a gross torque of the engine that exceeds known torsion losses by the desired output torque. To calibrate the system for the touch point identification process, the motor controller will first maintain the motor speed at desired idle rpm (around 850 to 900 rpm) with the clutch 14 fully disengaged, sending the appropriate request torque from the motor to the motor via the communications link SAE J1939 DL. When the motor control loop reaches its equilibrium, the magnitude of the torque request will be equal to that of the motor torsion losses (at the desired idle rpm). Then, the system will activate the inertial brake 60 to lock the input shaft and, in this way, land the driven side 14B of the clutch. The system will then request an engine torque equal to the engine torsion losses plus 10 foot pounds and then attempt to gradually engage the clutch to the 10 pound-foot level (that is, when the engine stabilizes at running speed at empty) . To do this, the system uses the value of the torque request and the motor speed as feedback references. As the clutch is being gradually linked, the load on the motor is increased and, therefore, the motor speed is reduced. Since the torque request is at the value of 10 foot pounds above the torsional losses of the engine, the linked clutch torque will be equal to 10 foot pounds when the engine speed is stabilized at the idle speed. The system will record the level of PWM that links 10 pound-feet of clutch torque and then repeat the process to link the clutch to another level, say 20 foot-pounds. The clutch touch point can then be obtained by simply extrapolating the two clutch engagement values (Figure 4B). This is possible because the torque capacity of the clutch 14, especially within relatively small increments (0 to 40 foot-pounds), is substantially linear relative to the PWM control signal applied to the solenoid 52A. Although the gross torque of the motor that is being generated by the motor is available in the data link, in a preferred embodiment, a more responsive control can be obtained assuming that the gross torque of the motor is equal to the gross torque requested the motor. Figure 5 is a flow diagram illustrating the touch point identification control logic of the present invention. As an alternative procedure, the clutch can be applied to the first and second values of the control parameter, increasing the output torque of the engine until the engine speed stabilizes to idling, and then fixing the torque capacity of the clutch equal to the output torque of the engine when running under vacuum. Accordingly, it can be seen that a new and improved touch point identification control system / method is provided. Although the present invention has been described with a certain degree of particularity, it will be understood that the description of the preferred embodiment is by way of example only and that numerous changes in form and detail are possible without departing from the spirit and scope of the invention. the invention, as claimed hereinafter.

Claims (15)

1. CLAIMS 1. A method for determining the value of a clutch control parameter signal corresponding to an incipient attachment position of a vehicle master clutch in a vehicle traction line system, including an electronically controlled internal combustion engine having an output member, a gear shift transmission, of multiple speeds, having an input shaft driven to said output member by said master control clutch, a clutch operator responding to said clutch control parameter signal to provide a torque transfer capability selected from said output member to said input shaft, an engine controller for controlling the fuel supply of said engine, said controller effective for feeding fuel to said engine to cause said engine to rotate. a selected engine speed and develop a torque Selected signal and provide serials indicative of engine speed and developed torsion, an effective input arrow braking device to delay the rotation of said input arrow, a system controller to receive input signals including signals indicative of ( i) the requested or sensed torque of the motor in said output member and (ii) the speed of the motor, and to process them according to logic rules for issuing command output signals to system actuators, including (i) said motor controller. engine, (ii) said clutch operator and (iii) said braking device of the input shaft, said method characterized by: (a) (i) applying said input arrow braking device to prevent rotation of said arrow of entry, (ii) cause said motor to develop a first twist in said exit member, (iii) apply said clutch until the engine speed stabilizes au the engine idle speed, and (iv) detecting as a first value of said control parameter the value of said parameter when the engine speed is stabilized at said idle speed; then (b) (i) applying said braking device of the input shaft to prevent rotation of said input shaft, (ii) causing said motor to develop a second twist different from said first torsion on said output member, ( iii) applying said clutch until the speed of the motor stabilizes at said idle speed, and (iv) detecting as the second value of said control parameter the value of said control when the speed of the motor is stabilized at said speed. march to the void; and (c) using said first value of said control parameter and said first torque value as a first point and said second value of said control parameter and said second torque value as a second point, defining a linear relationship between said values. of the control parameter and the clutch torque capacity.
2. 2. The method of claim 1, wherein said transmission is a mechanical transmission using positive jaw clutches.
3. 3. The method of claim 1, wherein said clutch is a wet clutch cooled with liquid.
4. The method of claim 1, wherein said clutch controller includes a solenoid controlled valve and a pulse width modulated electric power source applied to the solenoid of said valve, said clutch control parameter comprising the width modulation of pulse of said electrical energy.
5. The method of claim 1, wherein said first and second values are selected to provide a clutch torque capacity of less than ten percent (10%) of the maximum rated capacity of said clutch.
6. The method of claim 5, wherein said first and second values are from about 5 to 15 foot-pounds and about 15- to 30 foot-pounds, respectively.
7. The method of claim 1, wherein said system controller is microprocessor-based and said motor controller communicates with an electronic data link that complies with one of the SAE J1922, SAE J1939 or ISO 11898 protocols.
8. 8. The method of claim 1, wherein said clutch is made to be completely disengaged to cause said known torsional transfer capacity to be equal to zero.
9. 9. A method for determining the value of a clutch control parameter signal corresponding to an incipient attachment position of a vehicle master clutch in a vehicle traction line system, including an electronically controlled internal combustion engine having a output member, a gear shift transmission, of multiple speeds, having an input shaft driven to said output member by said master control clutch, a clutch operator responding to said clutch control parameter signal for providing a torque transfer capability selected from said output member to said input shaft, an engine controller for controlling the fuel supply of said engine, said controller effective for feeding fuel to said engine to cause said engine to rotate to a selected engine speed and develop a tight torque and provide signals indicative of the engine speed and developed torsion, an effective input arrow braking device for delaying the rotation of said input arrow, a system controller for receiving input signals including signals indicative of (i) ) the requested or sensed torque of the motor in said output member and (ii) the motor speed, and to process them according to logic rules for issuing command output signals to system actuators, including (i) said motor controller , (ii) said clutch operator and (iii) said braking device of the input arrow, said method characterized by: (a) (i) applying said input arrow braking device to prevent rotation of said arrow input, (ii) apply the clutch to cause the value of said clutch control parameter to assume a first known value, (iii) command the motor to rotate at running speed vacuum, and (iv) detecting as a first value of the torque capacity of the clutch the torsion in the output member of the engine when the idle speed is stabilized; then (b) (i) applying said braking device of the input shaft to prevent rotation of said input shaft, (ii) applying the clutch causing the value of said clutch control parameter to assume a second known different value. of said first known value, (iii) ordering the motor to rotate at idle speed, and (iv) detecting as a second value of said clutch torque capacity the torque on the output member of the motor when the speed is stabilized of vacuum gait; and (c) using said first value of said control parameter and said first torque value as a first point and said second value of said control parameter and said second torque value as a second point, defining a linear relationship between said values. of the control parameter and the clutch torque capacity. The method of claim 9, wherein said transmission is a mechanical transmission using positive jaw clutches. The method of claim 9, wherein said clutch is a wet clutch, cooled by liquid. The method of claim 9, wherein said clutch controller includes a solenoid controlled valve and a pulse width modulated electrical power source, applied to the solenoid of said valve, said clutch control parameter comprising width modulation. of pulse of said electrical energy. The method of claim 9, wherein said first and second values are selected to provide a clutch torque capacity of less than ten percent (10%) of the maximum rated capacity of said clutch. The method of claim 13, wherein said first and second values are about 5 to 15 foot-pounds and about 15 to 30 foot-pounds, respectively. The method of claim 9, wherein said system controller is microprocessor-based and said motor controller communicates with an electronic data link that complies with one of the SAE J1922, SAE J1939 or ISO 11898 protocols.